Carburetor



Sept. 22, 1925. y 1,554,619

G. M. BICKN ELL CARBURETOR Filed July 25. 1921 `of the idler tube inlet.

l'atentecl Sept. Z2, 1925.

UNITED STATES PATENT omer..

GEORGE M. SBIQKNELL, QF ST. LOUIS, MISSOURI cnnrunn'rcn.

Application filed .Tilly 25, 1921. Serial No. 487,222.

v T0 all whom t may concern.'

Be it known that I, GEORGE M. BIcKNnLr., a citizen of the United States,and resident of the city of St. Louis and State of Missouri, haveinvented certain new and usefullmprovements in Carburetors, of which thefollowing is a specification, containing a full, clear,.,andexaotdescription, `reference being had tothe accompanying drawings, formingapart hereof.

My invention relates to improvements in carburetors,.and has for itsprimary object the provision of a carburetor which `is soconstructed asto secure a more accurate adjustment of the mixture at idle enginespeed.

A further object is `to construct a carburetor which can be so adjustedas to secure a uniform and even mixture at the initial Fig.. 3 anenlarged fragmental section of the upper portion of the carburetorshowing the idler tube inlet, throttle valve and the reglating screw.

the construction of my d'evice I employl a carburetor having a casing fthaving an integrally formed float chamber 5 andin this float chamber ismounted the usual float and needle valvev 6. Formed integrally withinthe casing `4: is an air inlet 7 and a' mixing chamber 8. Below themixing chamber 8 and secured within the casing 4 is a choke or venturi 9into which the main fuel nozzle 10 extends. The lower end of the fuelnozzle o ning into the well 11. This well communicates with the passage13 opening into the float chamber 5. The passage 13 is provided with acalibrated plug 14 which regulates or prevents too 'rapid a flow offuelnto the well 11. Formed in the wall of the casing and between themain nozzle 10 andthe float chamber 5 is a fuel passage "'l'his fuel'passage way conducting fnie'ltothe engine at idle and initial throttle'openlngs. The lower end of the to construct a passage 15 opens into thepassage way 12 and is 'provided with a calibrated plug 16 which retardsthe flow of fuel into the passage way 15. The upper end ofthe passage 15communicates with the opening 17. A portion of this opening is screwthreaded to receive the .adjusting screw 18, whichadjusting screw isprovided with a reduced portion 19 which fits into the opening or port20.

This opening or port furnishes communi-v cation with the passage 15 andwith the suction chamber 21 of the carburetor. This port is preferablyelongated in form as illustrated in Fig.' 2. Mounted `immediately abovethe mixing chamber 8 is a throttle valve 22 which is so arranged thatwhen it is closed, it extends across the port 20, so that a portionthereof will be above the valve and a portion below, in other words,divide the port into two portions. Formed through the venturi andcommunicating with the passage 15 is a by-pass 23.

This ley-pass is so located that it will always be above the fuel level.v

The operation of my deviceis as follows:

A fter the carburetor has been connected i up, and proper fuelconnections made, the engine is cranked. When the engine commences torun, the throttle valveis shut oif as indicated in Figs. 1 and 3 and theadjustingscrew 18 is then screwed outward or inward until the desiredquantity `of idling mixture is obtained. This movement of the Yscrew 'isto adjust the size of the passage 211 between the edge of the throttlevalve 22 and the projection 19 formed on the screw 18. ,As the engineoperates a certain amount of air is drawn through the by-pass 23 whichis a short distance 'above the fuel level and consequently'will create apartial vacuum and pick up fuel and carry it to the opening 22, thenthrough the .passage 24 into the suction chamber 21.

This ickin up of fuel is also assisted by the air passing around thelvalve 22 in the mixing chamber entering -the port l20 and passingthrouoh the passage 24. The amount of mi. ture admitted is regulated bythe size of the passage 24a., which size is governed by the. reducedportion ofthe screw 18. It is possible, by advancing the screw 18 farenough, to close off the upper portion of the mixing chamber entirelywhen the throttle valve is closed, but it is preferable in ractice tohave the screw 18 backed out ar enough so that' the engine tirely closedor in its idling position.

will run slowly when the valve 22 is en- The adjustment of the .screw 18also regulates the amount of fuel mixture Supplied during `the initialthrottle opening, or until the main nozzle goes into action. `In thisway itis possible to throttle the engine so that the altomobile can berun at a very slow speed. i

While I have shown my device as -atv taehed to a carburetor having asingle main nozzle, it is obvious that my construction .can be adaptedto any plain tube type of carburetor now commercially used, withoutdeparting from the spirit of 'my invention. Having fullyy described myinvention, what I claim is: I I

1. In a carburetor,l a casing having a mixing chamber and asuctionvchamber, a

-throttle valve located betweeny said cham- Ato be moved toward and fromthe throttle valve for varying the size of Said unrobstructed passageway adjacent the suction chamber, whereby the amount of fuel and airentering thel suction chamber through said passage when the .valveisclosed, is`- regulated. f

2. In a. carburetor, a casing having a mixing chamber and a suctionchamber formed therein, a, throttle'valve located in said casing betweensaid chambers, a port formed in the side wall of said casing at thepoint of communication between said chambers,

said port beingyof greater. diameter than the thickness of the throttlevalve 'and adapted to be Abisected thereby when the valve is closed,whereby constant com-- munication between the mixing and lsuctionchambers is maintained, a fuel passage `formed in the wall of saidcasing and communicating with said port,` ascrew located in said casing,said screw provided 'with a reduced' cylindrical end adapted to be eX-tended into said port along the upper portion thereof and .be moved toand from the edge of the valve when the same is l" closed, whereby thesize of the passage way leading into the suction chamber is varied. 3;In a carburetor a casing provided with 'a port in its sidewall, meansfor supplying a mixture of -fuel and air to said port, a throttle valvemounted 1n sald caslng and adapted to intersectI the port when closed, ian adjusting screw carried by said casing, Y

said adjusting screw being provided with a cylindrical end adapted to'extend into the port whereby the size of the port may be varied byadjusting tihe cylindrical end to and from the throttle valve when thesame is closed. i

In testimony whereof, I have sigggned4 my name-to this specication.

' GEORGE M. BICKNELL. y

